CN108362682A - A kind of multimode fibre LIBS detection device based on compound constant enhanced spectrum - Google Patents
A kind of multimode fibre LIBS detection device based on compound constant enhanced spectrum Download PDFInfo
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- CN108362682A CN108362682A CN201810068505.XA CN201810068505A CN108362682A CN 108362682 A CN108362682 A CN 108362682A CN 201810068505 A CN201810068505 A CN 201810068505A CN 108362682 A CN108362682 A CN 108362682A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
- G01N21/718—Laser microanalysis, i.e. with formation of sample plasma
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N2021/0162—Arrangements or apparatus for facilitating the optical investigation using microprocessors for control of a sequence of operations, e.g. test, powering, switching, processing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/08—Optical fibres; light guides
- G01N2201/084—Fibres for remote transmission
Abstract
The invention discloses a kind of multimode fibre LIBS detection device based on compound constant enhanced spectrum, including LIBS probes couple collection system, three parts of control detecting system, wherein LIBS probes are made of optical fiber coupling head and cavity for focusing；It includes dichroscope, optical fiber focalizer, fiber optic collector to couple collection system；It includes nanosecond laser, spectrometer, programmable pulse delay generator, ICCD, computer to control detecting system.Laser, as transmission medium, sample to be tested surface breakdown induced plasma is focused on according to convex lens image-forming discipline by the present invention using multimode fibre, and the method for having used compound constant enhancing plasma resonance improves component spectrum intensity.The present invention can be achieved to analyze while multiple element, and safe operation is reliable, high sensitivity, high certainty of measurement, spectral signal-noise ratio is high, and detection limits are low, and analyze speed is fast, it is efficient, remote online monitoring can be carried out, the deficiency of traditional optical fiber LIBS detection devices is effectively met.
Description
Technical field
The invention belongs to laser-diagnose technology fields, are related to a kind of multimode fibre LIBS based on compound constant enhanced spectrum
Detector.
Background technology
For the mining applied to phosphorus ore and coal ash, the detection of uranium under different geological conditions, the environmental pollution in water
Analyte detection, the analysis of explosion residue object, the true and false discriminating of famous painting, the shape of the equipment key structure of industrial circles such as power plant exhaust detection
State detection, repair and evaluation are the important supports of social industrial production safety and economy.In order to ensure that detection device is being made
Dangerous defect and damage is not present in structure after making and in operation, it is desirable that nothing before and labour in-service to the progress of detection device critical component
Damage detection, evaluation and running effective monitoring.However for the high radioactivities such as ore extraction, energy power generation, environmental pollution,
The severe running environment such as high temperature, high pressure, high toxicity, conventional detection means, such as X-ray radiography technology, ultrasonic technique, vortex skill
Art can be only applied to shutdown and not operation stage, can not achieve remote on-line measurement, cannot fully meet under bad working environments
The demand of key equipment detection.
Laser induced breakdown spectroscopy (Laser Induced Breakdown Spectroscopy, hereinafter referred to as
LIBS technologies) by people's extensive concern, LIBS is to focus on compact medium surface based on high power pulsed laser to generate transient state
Plasma is realized qualitative to sample or fixed by detecting and analyzing the atom or ion characteristic spectral line that plasma emission goes out
Measure a kind of novel spectral measurement methods of analysis.The technology has huge potential in the fields such as fusion energy resource, national defence, industry
Application value can be detected steam superheating bend pipe etc. in high temperature, high pressure, the high production line radiated by LIBS technologies and is manually difficult to
The place of arrival.Compared with other detection means, LIBS technologies have apparent advantage：Remote online in situ detection, sample are micro-
Damage is even lossless, without sample preprocessing, it can be achieved that multiple element is analyzed simultaneously etc..
However, there is also following shortcomings for traditional optical fiber LIBS systems.First, traditional portable fiber-optic LIBS is visited
Examining system can not also adapt to the severe running environment such as high radioactivity, high temperature, high pressure (for example, the Central China University of Science and Technology, once knows wild goose etc.,
Portable laser probe analytical instrument based on optical fiber laser, [P], China, 2013107403189.20151104).Its
Secondary, traditional optical fiber LIBS systems need the laser that fibre optical transmission goes out becoming directional light by planoconvex spotlight when focusing breakdown
Sample to be tested surface is focused on using planoconvex spotlight；The mode of this collimation focusing is complicated, is difficult to control, and focuses formation
Hot spot is larger, and the effect of breakdown is poor.Furthermore the transmission laser power of traditional fiber LIBS systems is small, and transmission efficiency is low, spectrum letter
Make an uproar than low, cause measurement accuracy poor, testing result it is with a low credibility.There is presently no a kind of device of on-line monitoring or spies
Measurement equipment can effectively meet the needs of key equipment detects under bad working environments.
Invention content
It is an object of the invention to overcome the above-mentioned prior art, provide a kind of based on compound constant enhanced spectrum
Multimode fibre LIBS detection device focuses laser induced breakdown spectroscopy using imaging mode, is mainly used for quantification and qualification survey
Elemental composition in earnest matter.
In order to achieve the above objectives, the present invention is achieved by the following scheme：
A kind of multimode fibre LIBS detection device based on compound constant enhanced spectrum, including LIBS probes, coupling collect system
System and control detecting system；Wherein, LIBS probes include cavity for focusing, and the optical fiber coupling head mounted on cavity for focusing front end,
The first planoconvex spotlight is provided in cavity for focusing；It includes optical fiber focalizer, dichroscope and fiber optic collector to couple collection system；
It includes spectrometer, ICCD, nanosecond laser, computer and programmable pulse delay generator to control detecting system；Optical fiber is poly-
Burnt device is connected by Transmission Fibers with cavity for focusing, and is arranged in same light path with the first planoconvex spotlight；Fiber optic collector passes through
Optical fiber is collected with spectrometer to be connected.
The present invention, which further improves, to be：
The upper lower wall surface of cavity for focusing is respectively equipped with the air inlet that can be switched and gas outlet, air inlet and gas outlet with it is external
It is connected by conduit between gas chamber, and argon gas, helium and nitrogen is filled with into cavity for focusing and optical fiber coupling head by pipeline and used
In influence of the adjustment laser energy to LIBS spectrum caused by pipe under test；Cavity for focusing and fiber coupling are extracted by gas outlet
Air in head forms vacuum environment or the condition of different air pressures；By air inlet and gas outlet, manufacture is a variety of in LIBS pops one's head in
Gas medium environment or vacuum environment, to meet the media environment requirement of the laser detection element-specific of different wave length.
Optical fiber coupling head includes permanent magnet, magnet obligatory point and space constraint body；Space constraint body is cylinder barrel shaped,
Its outer surface be can completely be fitted closely with pipe under test wall surface mutually pass through face shape；The outer diameter of space constraint body is 8mm, with
It is closely connected by helicitic texture between cavity for focusing；The upper and lower part of magnet obligatory point opens up fluted, and permanent magnet is set
In two grooves；Rectangular groove length in magnet obligatory point is 8mm, width 5mm, is highly 8mm.
Cavity for focusing includes air inlet, gas outlet, closed slide, the first planoconvex spotlight, extension bar holder and fine motion controller；
Transmission Fibers are connected by the first optical fiber connector with cavity for focusing；Closed slide is mounted on lower center position in cavity for focusing, connects
Bar holder is mounted on closed slide, and the first planoconvex spotlight is mounted on extension bar holder；Optical fiber coupling head, the first planoconvex spotlight and
First optical fiber connector is in same light path, and the center of optical fiber coupling head, the center of the first planoconvex spotlight and the first optical fiber
The center of connector is on the same line；First optical fiber connector be placed on the first planoconvex spotlight in cavity for focusing one times of focal length it
Outside；A diameter of 25.4mm of first planoconvex spotlight, focal length 16mm.
Transmission Fibers and collection optical fiber are the multimode fibre of silica covering；The length of Transmission Fibers is 3m, optical fiber
Core diameter is 800 μm, numerical aperture 0.37, maximum power density 50kW/cm2；The length for collecting optical fiber is 1m, optical fiber core diameter
It is 400 μm, numerical aperture 0.22.
Transmission Fibers are connected by the second optical fiber connector with light focusing device；It collects optical fiber and passes through third optical fiber connector
It is connected with fiber optic collector.
Second optical fiber connector and third optical fiber connector are made of SMA905 stainless steels.
Optical fiber focalizer, dichroscope and fiber optic collector are respectively positioned on same light path；Optical fiber focalizer be mounted on two to
The reflecting surface side of Look mirror, fiber optic collector are mounted on the transmission plane side of dichroscope；Optical fiber focalizer is saturating by the second plano-convex
Mirror and the second optical fiber connector composition；Fiber optic collector is made of third planoconvex spotlight and third optical fiber connector；Optical fiber focuses
The third planoconvex spotlight in the second planoconvex spotlight and fiber optic collector in device is flat with the output laser beam axis of nanosecond laser
Row.
The output laser beam axis angle at 45 ° of dichroscope and nanosecond laser, dichroscope are short-pass dichroscope,
A diameter of 50.8mm, cutoff wavelength 805nm；A diameter of 12.7mm of second planoconvex spotlight, focal length 100mm；Third plano-convex
A diameter of 12.7mm of lens, focal length 40mm.
LIBS probes further include fine motion controller, and fine motion controller is mounted on outside the cavity of cavity for focusing, for controlling extension bar
Displacement of the junction of holder and closed slide on closed slide；Fine motion controller is connect with computer by electric signal.
Compared with prior art, the invention has the advantages that：
The present invention is based on the optical fiber LIBS detection devices of compound constant enhanced spectrum, are installed in bad working environments and are manually difficult to
On the detection track of the key structure reached, detected using the compound online remote in-situ of spectrum enhancing technology.Realize high radiation
Property, the demand that key equipment detects under the severe running environment such as high temperature, high pressure.The present invention can provide multiple gases dielectric ring
Border is pre-processed without the intercepted samples from pipeline configuration without to pipeline configuration, and the micro- damage of pipe surface is even lossless, can
It is analyzed while realizing multiple element, safe operation is reliable, and high certainty of measurement, analyze speed is fast, efficient.Finally, of the invention
Based on the multimode fibre LIBS detection device high sensitivity for meeting composite strengthening spectrum, spectral signal-noise ratio is high, and analyze speed is fast, measures
Safety, detection limits are low, can carry out remote online monitoring, effectively meet traditional optical fiber LIBS detection devices not
Foot.
Further, the numerical aperture of Transmission Fibers of the present invention is 0.37, and the numerical aperture for collecting optical fiber is 0.22, big number
Value aperture is conducive to being coupled into for optic fibre input end light, and in diversity of the output end due to multimode fibre and off-axis property
The laser of output is set to be difficult to focus target practice；Low numerical aperture provides lower luminous exitance and uniform spot size, this
It can contribute to focus on light beam after beam propagation.
Further, collimated laser beam of the present invention by dichroscope reflection is focused by the second planoconvex spotlight enters height
It being transmitted in power transmission optical fiber, the input terminal of the second optical fiber connector of Transmission Fibers is placed on behind focus at about 3mm,
To avoid the boundary that focuses energy damage multimode fibre core covering powerful in fiber coupling
Description of the drawings
Fig. 1 is the overall construction drawing of the multimode fibre LIBS detection device based on compound constant enhanced spectrum；
Fig. 2 is the schematic diagram that optical fiber coupling head is bonded that the surface breakdown induction of test tube road generates plasma plume；
Fig. 3 is the plasma radiation spectral line comparison diagram without constraint enhanced spectrum and compound constant enhanced spectrum；
Fig. 4 is the concrete structure schematic diagram of LIBS probe segments；
Fig. 5 is the work flow diagram of multimode fibre LIBS detection device parameter setting link；
Fig. 6 is the work flow diagram of multimode fibre LIBS detection device induced with laser link；
Fig. 7 is the work flow diagram that multimode fibre LIBS detection device collects spectrum link；
Fig. 8 is the work flow diagram of multimode fibre LIBS detection device processing analysis link.
In figure：The LIBS probe segments of A- multimode fibre LISB detectors；The coupling of B- multimode fibre LISB detectors is received
Collecting system；The control detecting system of C- multimode fibre LISB detectors；1- cavity for focusing；2- air inlets；3- permanent magnets；4- magnets
Obligatory point；5- space constraint bodies；6- optical fiber coupling heads；The gas outlets 7-；8- closed slides；9- planoconvex spotlights；10- extension bar holders；
11- fine motion controllers；12- optical fiber connectors；13- optical fiber connectors；14- optical fiber focalizers；15- Transmission Fibers；16- plano-convexs are saturating
Mirror；17- dichroscopes；18- planoconvex spotlights；19- fiber optic collectors；20- optical fiber connectors；21- collects optical fiber；22- spectrometers；
23-ICCD；24- nanosecond lasers；25- computers；26- programmable pulse delay generators；27- pipe under test；28- plasmas
Body feathers.
Specific implementation mode
The present invention is described in further detail below in conjunction with the accompanying drawings：
Referring to Fig. 1-8, the present invention is based on the multimode fibre LIBS detection devices for meeting constraint enhanced spectrum, including LIBS probes
A, tri- parts collection system B and control detecting system C are coupled；Wherein, LIBS probe As are by cavity for focusing 1 and optical fiber coupling head 6
Composition, optical fiber coupling head 6 are made of permanent magnet 3, magnet obligatory point 4 and space constraint body 5；Cavity for focusing 1 by air inlet 2, go out
Gas port 7, closed slide 8, the first planoconvex spotlight 9, extension bar holder 10 and fine motion controller 11 form；Couple collection system B packets
Include optical fiber focalizer 14, dichroscope 17 and fiber optic collector 19；Control detecting system C includes spectrometer 22, ICCD23, receives
Second laser 24, computer 25 and programmable pulse delay generator 26.
Optical fiber used in the present invention is the multimode fibre of silica covering.The length of Transmission Fibers 15 is 3m, optical fiber
Core diameter is 800 μm, numerical aperture 0.37, maximum power density 50kW/cm2；The length for collecting optical fiber 19 is 1m, fiber cores
Diameter is 400 μm, numerical aperture 0.22.The both ends of optical fiber are connected using SMA905 stainless steel optical fiber connectors.Large-numerical aperture
Be conducive to being coupled into for optic fibre input end light, and in output end since the diversity of multimode fibre and off-axis property make output
Laser be difficult to focus target practice；Low numerical aperture provides lower luminous exitance and uniform spot size, this can have
Help focus on light beam after beam propagation.The photon of plasma emission is along 15 reverse transfer of Transmission Fibers.At this point, Transmission Fibers 15
Laser output become photon input terminal, the laser input of Transmission Fibers 15 becomes the output end of photon.It can be according to reality
Need replacing different model, different length, different-diameter and different numerical aperture multimode fibre.
Closed slide 8 in LIBS probe As is mounted on lower center position in cavity for focusing 1, and extension bar holder 10 is mounted on flat
On row guide rail 8, the first planoconvex spotlight 9 is mounted on extension bar holder 10；Optical fiber coupling head 6, the first planoconvex spotlight 9, the first optical fiber
Connector 12 is in same light path, and 6 center of optical fiber coupling head, 9 center of the first planoconvex spotlight, 12 center of the first optical fiber connector
On the same line.Wherein, a diameter of 25.4mm of the first planoconvex spotlight 9, focal length 16mm.
Optical fiber focalizer 14, dichroscope 17 in coupling collection system B, fiber optic collector 19 are respectively positioned on same light path,
And the output laser beam axis angle at 45 ° of dichroscope 17 and nanosecond laser 24, the wherein cut-off of short-pass dichroscope 17
Wavelength is 805nm；Optical fiber focalizer 14 is mounted on the reflecting surface side of dichroscope 17, and fiber optic collector 19 is mounted on dichroic
The transmission plane side of mirror 17；Optical fiber focalizer 14 is made of the second planoconvex spotlight 16 and the second optical fiber connector 13, wherein second
A diameter of 12.7mm of planoconvex spotlight 16, focal length 100mm；Fiber optic collector 19 is by another third planoconvex spotlight 18 and third light
Fiber connector 20 forms, wherein a diameter of 12.7mm of third planoconvex spotlight 18, focal length 40mm.In optical fiber focalizer 14
Third planoconvex spotlight 18 in two planoconvex spotlights 16 and fiber optic collector 19 is flat with the output laser beam axis of nanosecond laser 24
Row.
Dichroscope 17 is short-pass dichroscope, a diameter of 50.8mm, cutoff wavelength 805nm.For 830-
The reflectivity of the light of 1300nm wavelength, dichroscope 17 can reach 96% or more；It is 400-792nm wavelength for wavelength
Light, thang-kng rate can also reach 90% or more.
It is focused by the second planoconvex spotlight 16 by the collimated laser beam that dichroscope 17 reflects and enters high power transmission light
It is transmitted in fibre 15, the input terminal of the second optical fiber connector 13 of Transmission Fibers 15 is placed on behind focus at about 3mm, to keep away
Exempt from the boundary that focuses energy damage multimode fibre core covering powerful in fiber coupling
The first optical fiber connector 12 being connect with LIBS probe As is placed on one times of coke of the first planoconvex spotlight 9 in cavity for focusing 1
Away from except, according to the imaging law of convex lens, handstand can be formed in the other side of the first planoconvex spotlight 9 by the laser of lens
Real image, in the other side of the first planoconvex spotlight 9, presence focuses laser in the process, the pipe under test 27 at optical fiber coupling head 6
Surface is placed exactly in the focal point of laser focusing.If U is object distance, V is image distance, and f is focal length, then full between object distance U and image distance V
The following relational expression of foot：
The laser of the 38J energy exported by nanosecond laser 24 passes through optical fiber focalizer 14, is entered by Transmission Fibers 15
3 in cavity for focusing, by the first planoconvex spotlight 9 focus after laser intensity can reach 33J, couple focusing efficiency reach 87% with
On, 27 surface of breakdown pipe under test can successfully induce plasma plume 28.
Fine motion controller 11 used in the present invention is mounted on outside the cavity of cavity for focusing 1, control extension bar holder 10 with it is parallel
Displacement of the junction of guide rail 8 on closed slide 8.Fine motion controller 11 is connect with computer 25 by electric signal, Ke Yitong
Crossing software control and regulation can also be adjusted manually, and control accuracy is up to 10 μm.
11 transmission telecommunications number of fine motion controller, the action of control fine motion controller 11 can be given by computer 25.Fine motion
Controller 11 drives movement of the extension bar holder 10 on closed slide 8, micro- to change the front and back position of the first planoconvex spotlight 9
The distance between the first optical fiber connector 12 and the first planoconvex spotlight 9 U are adjusted, and then it is another in the first planoconvex spotlight 9 to change laser
The focal position that side focuses, i.e. image distance V so that the most pronounced effects of plasma caused by laser breakdown pipe under test 27.
Nanosecond laser 24 used in the present invention is Nd：YAG nanosecond lasers, the laser is under second harmonic with 1-
10Hz working frequencies run (1064nm).Pulse width FWHM is 10ns, and maximum impulse energy is 150mJ, laser beam spot sizes
For 6mm.
Fig. 2 is the schematic diagram that optical fiber coupling head 6 is bonded that 27 surface breakdown of pipe under test induction generates plasma plume 28.Light
The outer surface of space constraint body 5 in fiber coupling head 6 is designed as mutually passing through face shape, can closely be pasted completely with 27 wall surface of pipe under test
It closes.The outer diameter of space constraint body 5 is 8mm, is closely connect by helicitic texture between cavity for focusing 1.According to pipe under test 27
The difference of radius size, the present invention devise and 27 wall surface of the pipe under test of a diameter of 20cm, 25cm, 50cm, 75cm, 100cm
The optical fiber coupling head 6 of the different model space constraint body 5 of adaptable binding face.The present invention can replace different knots according to practical
The optical fiber coupling head 6 of structure, different model and different dimensional parameters carrys out meet demand.
Different recommendations is equipped on software in computer 25 away from U, i.e. the first optical fiber connector 12 and the first plano-convex
The distance between lens 9 correspond to the length of different space constraint bodies 5.After replacing optical fiber coupling head 6 of different length,
By the length of the input optical fibre coupling head 6 into software, for software by automatic adjusument object distance U, computer 25 controls fine motion control
Device 11 finely tunes the position of the first planoconvex spotlight 9 by the best object distance U of the theory calculated so that laser is in the first planoconvex spotlight
The focal position that 9 other sides focus just falls within the surface of pipe under test 27, occurs to puncture and generates plasma plume 28.Herein
On, it can also be adjusted between the first optical fiber connector 12 and the first planoconvex spotlight 9 by manual rotation fine motion controller 11
Distance is allowed to obtain the effect of more significant laser breakdown induced plasma.
Magnet obligatory point 4 by optical fiber coupling head 6 top and the bottom groove and the permanent magnet 3 that is placed in one form.Magnetic
Rectangular groove length in body obligatory point 4 is 8mm, width 5mm, is highly 8mm.It is put into permanent magnet 3 in a groove
An approximate uniform magnetic field can be formed in gap therebetween, forms the magnetically confined condition of laser induced plasma.By simultaneously
The pole orientation of the change permanent magnet 3 that two grooves are placed up and down, can obtain the opposite approximate uniform magnetic field in direction.The present invention
The permanent magnet that different materials can be replaced according to demand forms different confining magnetic fields.
Space constraint body 5 is cylinder barrel shaped, the plasma plume 28 and punching that 27 surface of pipe under test is generated by laser breakdown
It hits wave and bumps against the cylinder shape inner wall of space constraint body 5 during to external diffusion and reflect, be radially propagated back to center
Come, the reflected slow plasma of shock wave opposite direction external diffusion causes two-dimensional constrains, strengthens plasma
Luminous intensity.The present invention be equipped with internal diameter from 3-5mm, length from the space constraint body 5 of the different dimensional parameters of 5-10mm, can basis
Demand obtains the plasma that different degrees of space constraint is reinforced.
The present invention is during laser focuses on 27 surface breakdown of pipe under test induction and generates plasma plume 28, by magnetic field
Constraint and cylindrical space constraint are combined, and constitute the compound constant enhancing plasma of the double constraints based on magnetic field and space
Radiation, can be greatly enhanced the spectral intensity of LIBS, to improve detectivity and detection limits.Fig. 3 is without about
The plasma radiation spectral line comparison diagram of beam enhanced spectrum and compound constant enhanced spectrum, it can be seen that increased based on compound constant is met
The detection system of strong spectral is compared with the detection system of no compound constant enhanced spectrum, the intensity of spectral line of measured radiation spectrum
Maximum intensification factor is up to 15 times or more.
Fig. 4 gives the concrete structure schematic diagram of LIBS probe As part, and wherein optical fiber coupling head 6 and cavity for focusing 1 is all made of
Heat safe silica glass material is made.It can be by the microcam or high-resolution monitoring and observation of scene placement to optical fiber coupling
The luminous intensity of laser focus position, plasma in syncephalon 6；Observe the position of the first planoconvex spotlight 9 in cavity for focusing 1
Information, it is convenient that fine motion controller 11 is controlled by computer 25, to realize first plano-convex of the fine tuning mounted on extension bar holder 10
The front and back position of lens 9 is allowed to obtain the effect of more significant laser breakdown induced plasma by changing the size of object distance U
Fruit.
The upper lower wall surface of cavity for focusing 1 is respectively equipped with switchable air inlet 2 and gas outlet 7, air inlet 2 and gas outlet 7 with
It is connected by conduit between external gas chamber, argon gas (Ar), helium is filled with into cavity for focusing 1 and optical fiber coupling head 6 by pipeline
(He) and influence of the gas mediums adjustment laser energy such as nitrogen (N2) to LIBS spectrum caused by pipe under test 27；Pass through
Gas outlet 7 can extract the air in cavity for focusing 1 and optical fiber coupling head 6 and form vacuum environment or the condition of different air pressures.Pass through
Air inlet 2 and gas outlet 7 can manufacture multiple gases media environment or vacuum environment in LIBS probe As, to meet different waves
The media environment requirement of long laser detection element-specific.
The specific workflow of the present invention is as follows：
1. parameter setting
As shown in the work flow diagram of the parameter setting link of Fig. 5, the optical fiber coupling head of suitable dimension model is selected first
6, and using 11 automatic adjusument object distance U of software control fine motion controller, nanosecond laser 24 is operated in internal trigger pattern, is swashed
Light device interval sends out continuous impulse.The parameter of programmable pulse delay generator 26 is set by software, changes nanosecond laser
The delay of 24 optical signals and ICCD23 gate-width signals so that the spectrogram observed on the software of computer 25 is effect
Preferable linearized radiation spectrogram.The position of the first planoconvex spotlight 9 is adjusted by software finely tunes fine motion controller 11 so that poly-
The luminous intensity for the plasma plume 28 that laser breakdown induction of the coke on 27 surface of pipe under test produces is maximum, shows spectrum
It is collected the intensity of spectral line maximum from spectrometer 22 in line intensity.
2. induced with laser
As illustrated in flow chart as shown in fig. 6, the manufacture inspection in cavity for focusing 1 and optical fiber coupling head 6 by air inlet 2 and gas outlet 7
Survey required gas medium environment when element；The operating mode of nanosecond laser 24 is changed to external trigger on software, is passed through
Software controls programmable pulse delay generator 26 and controls the light extraction of nanosecond laser 24 and the gate-width signal of spectrometer 22.Nanosecond
The wavelength sent out in laser 24 is that the laser of 1060nm is reflected by short-pass dichroscope 17 in optical fiber focalizer 14,
And the angle of laser and dichroscope is 45 °；Laser into optical fiber focalizer 14 focuses entrance by the second planoconvex spotlight 16
It is transmitted in high power transmission optical fiber 15, the laser projected from Transmission Fibers 15 enters in cavity for focusing 1；Transmission Fibers 15 1
The fiber connector 10 of side is located at except one times of focal length of the first planoconvex spotlight 9, can be saturating by the laser of the first planoconvex spotlight 9
The other side of mirror, which exists, to be focused, and is irradiated to 27 surface of pipe under test and is generated plasma plume 28.
3. collecting spectrum
Fig. 7 is the work flow diagram that laser breakdown induction generates detector collection spectrum after plasma.Plasma plume 28
Radiation by the compound constant of optical fiber coupling head 6 enhancing after, since light path is reversible, plasma plume 28 emit light
Son is focused on by the first planoconvex spotlight 9 in cavity for focusing 1 in first optical fiber connector 12 of 15 side of Transmission Fibers；Plasma
Radiated photons are along 15 reverse transfer of Transmission Fibers.At this point, the laser output of Transmission Fibers 15 becomes photon input terminal, light is transmitted
The laser input of fibre 15 becomes the output end of photon.The light beam projected from the second optical fiber connector 13 passes through the second planoconvex spotlight
16 become directional light, and directional light is entered by dichroscope 17 in fiber optic collector；Light beam into fiber optic collector 19 passes through
It crosses third planoconvex spotlight 18 to focus in collection optical fiber 19, and then is input in spectrometer 22.
4. processing analysis
Fig. 8 is the course of work for the spectroscopic data being collected into system processing analysis previous step.Spectrometer 22 every time into
Before the measurement of row pipe under test 27, the sampling of environmental background spectrum will be carried out.When measuring every time, nanosecond laser 24 will be spaced
Launch the pulse laser of 50 hairs time, the plasma spectrometry that each 27 surface of laser breakdown pipe under test generates is passed by light path
It is defeated in spectrometer 22；Spectrometer 22 is sent out cumulative be transmitted in computer 25 of spectrum that subpulse generates by collected 50 and is provided
To user, the LIBS component spectrums information in obtained spectroscopic data and database can be carried out analysis comparison by software automatically,
Element species and corresponding the intensity of spectral line contained in user's pipe under test 27 are supplied to, and can be further bent by calibrating
Line determines the constituent content in pipe under test 27.
Optical fiber used in the present invention is the multimode fibre of silica covering, and the both ends of optical fiber are connected using stainless steel optical fiber
Connect device connection.It is connected by Transmission Fibers between optical fiber focalizer and LIBS probes；Pass through receipts between light collector and spectrometer
Collect optical fiber connection.Compared to single mode optical fiber, multimode fibre core diameter is thicker, and transmission energy is larger, there is no excessive loss, at
This price is relatively low, and advantage is had more in the laser transmission of short-distance and medium-distance.In the present invention, different shaped can be replaced according to actual needs
Number, the multimode fibre of different-diameter and different numerical aperture.
The principle of the present invention：
The top and the bottom of magnet obligatory point in optical fiber coupling head are provided with rectangular groove, are put into a groove forever
Long property magnet can form an approximate uniform magnetic field in gap therebetween, form the magnetically confined condition of laser induced plasma.
The permanent magnet that the present invention can replace different materials according to demand forms different confining magnetic fields.
The present invention is focused in laser in pipe under test surface breakdown induction generation plasma process, by magnetically confined and circle
Cylindrical space constraint is combined, and constitutes the compound constant enhancing plasma radiation of the double constraints based on magnetic field and space, energy
The spectral intensity of LIBS is enough greatly enhanced, to improve detectivity and detection limits.
Switchable air inlet and gas outlet are equipped in cavity for focusing, by leading between air inlet and gas outlet and external gas chamber
Pipe connects.Multiple gases media environment or vacuum environment can be manufactured in LIBS pops one's head in by air inlet and gas outlet, with full
The media environment requirement of the laser detection element-specific of sufficient different wave length.
Fine motion controller is connect with computer by electric signal, can transmit telecommunications to fine motion controller by computer
Number, to control movement of the extension bar holder on closed slide.Computer respectively with programmable pulse delay generator and spectrum
Instrument connects simultaneously, is delayed using computer installation and controls nanosecond laser and gate ICCD.The collected light of spectrometer institute
Spectrum signal, which is transferred on computer, carries out subsequent spectrum analysis and algorithm process.
The above content is merely illustrative of the invention's technical idea, and protection scope of the present invention cannot be limited with this, every to press
According to technological thought proposed by the present invention, any change done on the basis of technical solution each falls within claims of the present invention
Protection domain within.
Claims (10)
1. a kind of multimode fibre LIBS detection device based on compound constant enhanced spectrum, which is characterized in that pop one's head in including LIBS
(A), coupling collection system (B) and control detecting system (C)；Wherein, LIBS probes (A) include cavity for focusing (1), and installation
Optical fiber coupling head (6) in cavity for focusing (1) front end, cavity for focusing (1) is interior to be provided with the first planoconvex spotlight (9)；Couple collection system
(B) include optical fiber focalizer (14), dichroscope (17) and fiber optic collector (19)；It includes spectrum to control detecting system (C)
Instrument (22), ICCD (23), nanosecond laser (24), computer (25) and programmable pulse delay generator (26)；Optical fiber is poly-
Burnt device (14) is connected by Transmission Fibers (15) with cavity for focusing (1), and is arranged in same light path with the first planoconvex spotlight (9)；
Fiber optic collector (19) is connected by collecting optical fiber (21) with spectrometer (22).
2. the multimode fibre LIBS detection device according to claim 1 based on compound constant enhanced spectrum, which is characterized in that
The upper lower wall surface of cavity for focusing (1) is respectively equipped with the air inlet (2) that can be switched and gas outlet (7), air inlet (2) and gas outlet
(7) connect by conduit between external gas chamber, and by pipeline to cavity for focusing (1) and optical fiber coupling head (6) it is interior be filled with argon gas,
Helium and nitrogen are for adjusting influence of the laser energy to LIBS spectrum caused by pipe under test (27)；Pass through gas outlet
(7) it extracts the air in cavity for focusing (1) and optical fiber coupling head (6) and forms vacuum environment or the condition of different air pressures；Pass through air inlet
Mouth (2) and gas outlet (7) manufacture multiple gases media environment or vacuum environment in LIBS probes (A), to meet different wave length
Laser detection element-specific media environment requirement.
3. the multimode fibre LIBS detection device according to claim 1 based on compound constant enhanced spectrum, which is characterized in that
Optical fiber coupling head (6) includes permanent magnet (3), magnet obligatory point (4) and space constraint body (5)；Space constraint body (5) is circle
Tubular, outer surface be can completely be fitted closely with pipe under test (27) wall surface mutually pass through face shape；Space constraint body (5)
Outer diameter be 8mm, closely connect by helicitic texture between cavity for focusing (1)；It opens the upper and lower part of magnet obligatory point (4)
Equipped with groove, permanent magnet (3) is placed in two grooves；Rectangular groove length in magnet obligatory point (4) is 8mm, width
It is highly 8mm for 5mm.
4. the multimode fibre LIBS detection device based on compound constant enhanced spectrum according to claim 1-3 any one,
It is characterized in that, cavity for focusing (1) includes air inlet (2), gas outlet (7), closed slide (8), the first planoconvex spotlight (9), extension bar
Holder (10) and fine motion controller (11)；Transmission Fibers (15) are connected by the first optical fiber connector (12) with cavity for focusing (1)；
Closed slide (8) is mounted on cavity for focusing (1) interior lower center position, and extension bar holder (10) is mounted on closed slide (8), and first
Planoconvex spotlight (9) is mounted on extension bar holder (10)；Optical fiber coupling head (6), the first planoconvex spotlight (9) and the first optical fiber connector
(12) in same light path, and the center of optical fiber coupling head (6), the center of the first planoconvex spotlight (9) and the connection of the first optical fiber
The center of device (12) is on the same line；First optical fiber connector (12) is placed on the first planoconvex spotlight (9) in cavity for focusing (1)
Except one times of focal length；A diameter of 25.4mm of first planoconvex spotlight (9), focal length 16mm.
5. the multimode fibre LIBS detection device according to claim 1 based on compound constant enhanced spectrum, which is characterized in that
Transmission Fibers (15) and collection optical fiber (21) are the multimode fibre of silica covering；The length of Transmission Fibers (15) is 3m,
Optical fiber core diameter is 800 μm, numerical aperture 0.37, maximum power density 50kW/cm2；The length for collecting optical fiber (19) is 1m,
Optical fiber core diameter is 400 μm, numerical aperture 0.22.
6. the multimode fibre LIBS detection device based on compound constant enhanced spectrum, feature exist according to claim 1 or 5
In Transmission Fibers (15) are connected by the second optical fiber connector (13) with light focusing device (14)；Optical fiber (21) is collected by the
Three optical fiber connectors (20) are connected with fiber optic collector (19).
7. the multimode fibre LIBS detection device according to claim 6 based on compound constant enhanced spectrum, which is characterized in that
Second optical fiber connector (13) and third optical fiber connector (20) are made of SMA905 stainless steels.
8. the multimode fibre LIBS detection device according to claim 1 based on compound constant enhanced spectrum, which is characterized in that
Optical fiber focalizer (14), dichroscope (17) and fiber optic collector (19) are respectively positioned on same light path；Optical fiber focalizer (14) is pacified
Mounted in the reflecting surface side of dichroscope (17), fiber optic collector (19) is mounted on the transmission plane side of dichroscope (17)；Light
Fine focalizer (14) is made of the second planoconvex spotlight (16) and the second optical fiber connector (13)；Fiber optic collector (19) is put down by third
Convex lens (18) and third optical fiber connector (20) composition；The second planoconvex spotlight (16) and optical fiber in optical fiber focalizer (14) are received
Third planoconvex spotlight (18) in storage (19) is parallel with the output laser beam axis of nanosecond laser (24).
9. the multimode fibre LIBS detection device according to claim 8 based on compound constant enhanced spectrum, which is characterized in that
The output laser beam axis angle at 45 ° of dichroscope (17) and nanosecond laser (24), dichroscope (17) be short-pass two to
Look mirror, a diameter of 50.8mm, cutoff wavelength 805nm；A diameter of 12.7mm of second planoconvex spotlight (16), focal length 100mm；
A diameter of 12.7mm of third planoconvex spotlight (18), focal length 40mm.
10. the multimode fibre LIBS detection device according to claim 1 based on compound constant enhanced spectrum, feature exist
In LIBS probes (A) further include fine motion controller (11), and fine motion controller (11) is mounted on outside the cavity of cavity for focusing (1), is used for
Displacement of the junction of control extension bar holder (10) and closed slide (8) on closed slide (8)；Fine motion controller (11) and meter
Calculation machine (25) is connected by electric signal.
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108963736A (en) * | 2018-08-16 | 2018-12-07 | 深圳番越光电有限公司 | A kind of high-peak power picosecond and nanosecond short-wavelength light fibre laser |
| CN109557057A (en) * | 2018-11-19 | 2019-04-02 | 西安交通大学 | A kind of optical fiber LIBS detection device and method in Nuclear power plant main pipeline |
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| CN114942101A (en) * | 2022-01-28 | 2022-08-26 | 西安交通大学 | Vacuum degree on-line detection system and method of single optical fiber laser induced breakdown spectroscopy |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202854037U (en) * | 2012-09-10 | 2013-04-03 | 北京宝瑞光电科技有限公司 | Integration laser-induced intensified plasma spectrum acquisition system |
| CN103743710A (en) * | 2013-12-28 | 2014-04-23 | 华中科技大学 | Portable laser probe component analyzer based on optical fiber laser |
| CN105548094A (en) * | 2016-01-22 | 2016-05-04 | 清华大学 | Twin-lens based LIBS system for trace heavy metal detection |
| US20170234800A1 (en) * | 2016-02-12 | 2017-08-17 | Bwt Property, Inc. | Laser Induced Breakdown Spectroscopy (LIBS) Apparatus for the Detection of Mineral and Metal Contamination in Liquid Samples |
| CN107158579A (en) * | 2017-06-29 | 2017-09-15 | 佛山科学技术学院 | It is a kind of can skin lesion clear be automatically positioned optical therapeutic instrument and control method |
| CN206920344U (en) * | 2017-06-06 | 2018-01-23 | 浙江大学 | A kind of dipulse excites the spectrum detection device of magnetic field space double constraints enhancing plasma |
-
2018
- 2018-01-24 CN CN201810068505.XA patent/CN108362682A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202854037U (en) * | 2012-09-10 | 2013-04-03 | 北京宝瑞光电科技有限公司 | Integration laser-induced intensified plasma spectrum acquisition system |
| CN103743710A (en) * | 2013-12-28 | 2014-04-23 | 华中科技大学 | Portable laser probe component analyzer based on optical fiber laser |
| CN105548094A (en) * | 2016-01-22 | 2016-05-04 | 清华大学 | Twin-lens based LIBS system for trace heavy metal detection |
| US20170234800A1 (en) * | 2016-02-12 | 2017-08-17 | Bwt Property, Inc. | Laser Induced Breakdown Spectroscopy (LIBS) Apparatus for the Detection of Mineral and Metal Contamination in Liquid Samples |
| CN206920344U (en) * | 2017-06-06 | 2018-01-23 | 浙江大学 | A kind of dipulse excites the spectrum detection device of magnetic field space double constraints enhancing plasma |
| CN107158579A (en) * | 2017-06-29 | 2017-09-15 | 佛山科学技术学院 | It is a kind of can skin lesion clear be automatically positioned optical therapeutic instrument and control method |
Non-Patent Citations (4)
| Title |
|---|
| 刘广玉: "《微传感器设计、制造与应用》", 29 February 2008, 北京航空航天大学出版社 * |
| 刘木华: "《农产品质量安全光学无损检测技术及应用》", 30 June 2011, 华中科技大学出版社 * |
| 李冬雪等: "基于空心光纤技术产生高能量周期量级脉冲压缩", 《中国激光》 * |
| 殷刚，周军: "光纤共聚焦显微内窥镜活体内实时", 《光学仪器》 * |
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|---|---|---|---|---|
| CN108963736A (en) * | 2018-08-16 | 2018-12-07 | 深圳番越光电有限公司 | A kind of high-peak power picosecond and nanosecond short-wavelength light fibre laser |
| CN109557057A (en) * | 2018-11-19 | 2019-04-02 | 西安交通大学 | A kind of optical fiber LIBS detection device and method in Nuclear power plant main pipeline |
| WO2020103361A1 (en) * | 2018-11-19 | 2020-05-28 | 西安交通大学 | Optical fiber laser induced breakdown spectroscopy detection device and method |
| US11346781B2 (en) | 2018-11-19 | 2022-05-31 | Xi'an Jiaotong University | Optical fiber laser induced breakdown spectroscopy detection device and method |
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